Internal mandrel for sectional-boiler headers



A. COTTON INTERNAL MANDREL FOR SECTIONAL BOILER HEADERS Jan. 3, 1928.

Filed Nov. 11, 1925 Patented Jan. 3, 1928;

lJNlTEDST-ATES ALFRED COTTON, DECEASED, LATE OF ST.

PATENT ,QFFICE.

LOUIS, MISSOURI, BY LAURA I. COTTON,

EX'EOUTRIX, OF ST. LOUIS, MISSOURI, ASSIGNOR TO HEINE'BOILER COMPANY, ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI. I

INTERNAL MANDREL FORSECTIONAL-BOILER HEADERS.

Application filed November scribed, that is of novel construction.

Figure 1 of thedrawings is a perspective View of a Cotton boiler header.

Figure 2 is a longitudinal sectional View of a mandrel embodying the present invention, showing the mandrel expanded and arranged in operative positioninside of the header.

Figure 3 is a similar View, showing the mandrel partly collapsed.

Figure 4 is a longitudinal sectional view, showing the collapsible supporting means for the die bars removed, prcpaatory to withdrawing the die bars from the header; and I Figure 5 is a sectional View, illustrating a modification of the invention.

In the drawings m designates a sectional boiler header of the kind described in the said Cotton patent that is produced by arranging a circular or oval metal tube between two side dies and a front and rear die, and then moving said dies inwardly towards the longitudinal axis of the tube, so as to deform the tube in such a way as to produce a header having corrugated lateral sides and front and rear sides that have flat seat faces 1 disposedat an angle to the longitudinal axis of the header, which fiat seat faces are, adapted to have hand holes and tube holes formed in same. During the deforming operation the portions of the tube that constitute the flat scat faces are internally supported by the mandrel that forms the subject-matter of this present application.

Said. mandrel is composed of two die bars A, each of which has a plurality of rigid die elements 2 arranged on the outer face of same, and a collapsible supporting means I arranged between said die bars for holding them infrigid relation during the deform-I ing operation, said supporting means being i so constructed that it can be manipulated at 11, 1925. Serial No. 68,374.

the completion of the deforming operation to partially collapse the mandrel, and thus prevent the die elements 2 from being gripped-by the header as it shrinks. Said collapsible supporting means constitutes a unit that separate and distinct from the die bars and the particular construction of said supporting means is immaterial, so far as the broad idea is concerned, so long as it is of such design that it canjbe bodily removed from operative position between the die bars, and moreover-,can be manipulated easily at the completion of the deforming operation to permit the die bars to move inwardly sufficiently to prevent the die elements 2 fronrbeing gripped by the header as it cools off and shrinks. In the form of the invention shown in Figures 2, o

0 and 4: the collapsible supporting means for the die bars A is composed of a center 7 D provided with cooperating, oppositely-' i inclined surfaces 3 that bear on each other. Irrespective of the particular design of the dievbar supporting means, it must be constructed so that it will hold the die bars in rigid spaced relation during the deforming operation; so that it can be easily ma ni'pulated at the completion of the deforming operation to collapse the mandrel suliiciently to prevent the die elements of same from being seized or gripped by the front and rear dies of the press and so that it can be bodily removed from between the die bars A, thereby permitting said die bars to be withdrawn from the header. In the mandrel shown in Figure 1 the membersC have smooth surfaces on their outersides, preferably n'iachined surfaces, that bear against smooth surfaces on'the inner sides of the die bars A. l

During the deforming operation the members B- and C are disposed in substantially the relation shown in Figure 2, and are held in this relation and connected with the die bars by any suitable means that will cause said parts toco-operate with each through the die bars A and through the members B and C effectively prevents relative longitudinal movement of the members B and C and also causes said members B and Q to be securely locked to the die bars. At the completion of the deformingoperation the tapered pin E is withdrawn from the holes provided for same in the die bars and.

in the members B and G, and thereafter the member B isv moved longitudinally of the members C in a direction to cause the wedges on said member B to move upwardly on the inclined surfaces on the members C, thereby relieving the pressure which forces said die bars apart,'and consequently, permitting said die bars to move inwardly sufficiently to partially collapse the mandrel. and prevent the die elements 2 of same from being grippedby the header when it shrinks. In most instances the wedge member B will be provided at its upper end with a hole 4: for receiving the hook of a hoisting apparatus that is used to withdraw the collapsible die bar supporting means from operative position between the die bars, the members B and C being joined together at their upper ends by a bolt 5 whiehpasses throi'lgh holes in. the members 0 and through an elongated sloth? in the member B that provides for the slight upward movement of the member B after the tapered pin- E at the upper end of the mandrel has been withdrawn.

Inusing thismandrel, the die bars A and nilembers B and G are first arranged in the relation shownin Figure, 2 and secured together by the bolt 5 and the tapered pin F or, equivalent means. Said mandrel is then arranged-in an upright position in the press inside of the tube that is to be deformed into a header, so that when the dies of the press move inwardly, the die elements 2 of the mandrel will internally support the portions of the tube that constitute the flat seat faces 1 of the header. At the completion of the deforming operation the pin E is withdrawn from the die bars A and members B and C and the wedge member B is then moved upwardly slightly relatively to the members C, as shown in F lgure 8, so

asto reduce the width of the supporting unit for the die, bars, thereby causing the mandrel to collapse sufficiently to permit the die elements 2 on the diebars to break away from the header when it starts to cool and shrink. Thereafter, the unit consisting of themembers B andC, iswithdrawn longitudinally. from operative position between the die bars A so as to permit said die bars to be moved inwardly towards each other,

as shown in Figure 4, and then withdrawn from the header. A mandrel of the construct on above described can be assembled and disassembled easily, as-there are praetically only five main parts; it can be manipulated easily at the completion of the deforming operation, so as to effectively prevent means of same is composed ofonly two memb-ers, namely, the members D. To collapse the mandrel shown in Figure 5 it is only necessary to withdraw the transverse pin E that extends through the die bars and through the members D and then move one of the members D upwardly relatively to the other in adirection to displace the oppositely-inclined surfaces 3 on said members sutliciently to slightly reduce the width of the supporting unit of the mandrel that takes up the shocks and strains to which the die bars are subjected during the deforming operation. After said unit has been withdrawn longitudinally from operative position between the die bars, said die bars can be removed easily from the header.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patentis:

1. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars arranged in opposed relation and provided with die elements, .and a collapsible means interposed between said die bars for rigidly supporting said die bars during the deforming operation, comprisng a plurality of members constructed so that the width or thickness of said collapsible means can be reduced quickly at the completion of the deforn'iing operation by relative longitudinal movement of said members, thereby preventing the header from gripping the die elements. 7

2. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars provided with die elements, and ameans for rigidly supporting the die bars during the till llH)

deforming operation consisting of a collapseliminate the possibility of the die elements being seized or gripped by the header as it shrinks I i 3. A mandrel for internally supporting a tube that is being deformed toproduce a sectional header, consisting of two die bars provided with die elements, and a means interposed. between the die bars for rigidly sup N porting the die bars during the deforming operation composed of a plurality of members provided with co-operating inclined surfaces combined so as to form a unit that can be bodily removed from operative position between the die bars and whose width can be varied by changing the relative position of the co-operating inclined surfaces of said members.

l. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars provided with die elements, a removable unit between the die bars for rigidly supporting the same during the deforming operation composed of a plurality of members provided with oppositely-inclined surfaces that cmoperate with each other to vary thewidth of said unit when one member of the unit is moved longitudinally relatively to another member of the unit, and means for preventing relative longitudinal movement of the unit members during the deforming operation.

5. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars pr0- vided with die elements, a removable unit between the die bars for rigidly supporting the same during the deforming operation composed of a plurality of members provided with oppositely-inclined surfaces that cooperate with each other to vary the width of said unit when one member of the unit is moved longitudinally relatively toanother member of the unit, and means for holding said unit in operative relationship with the die bars and for preventing relative longitudinal movement of the-unit members during the deforming operation.

6. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars provi'ded on their outer sides with die elements and on their inner sides with smooth surfaces, and a removable, collapsible unit interposed between the die bars and provided with smooth surfaces that bear against the smooth inner faces of the die bars.

7. A mandrel for internally supporting a tube that is being deformed to produce a sectional header, consisting of two die bars provided on their outer sides with die elements and on their-inner sides with smooth surfaces, a removable, collapsible unit interposed between the die bars and provided with smooth surfaces that bear against the smooth inner faces of the die bars, and a removable device in said unit and die bars that joins said parts together and also prevents said unit from collapsing.

SLA mandrel for internally supporting a tube that 1s being deformed to produce a sectional header, consisting of two die bars provided with die elements, and a collapsible unit between said die bars for supporting them rigidly during the deforming opera-.

tion, composed of a center member provided with wedges and two members embracing said center member and provided with oppositely-inclined surfaces that bear against said wedges, a fastening device for joining said unit members together, and an independent means for holding said unit in operative relationship with the die bars.

LAURA P. COTTON, Eweoutm'm do bonds non wider the l V ZZZ of Alfred Cotton, deceased. 

